Supporting Information

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1 Electronic Supplementary Material (ESI) for Journal of Materials Chemistry A. This journal is The Royal Society of Chemistry 2016 Experimental and related aspects Supporting Information Characterization: The synthesized materials were characterized by different techniques. X-ray diffraction (XRD) data of all samples were collected by the X Pert PRO PANanalytical equipment (Bragg- Brentano geometry with automatic divergence slits, position sensitive detector, continuous mode, room temperature, Cu-Kα radiation, Ni filter. The powder samples were dropped onto silicon wafer with grease, and measured at the same equipment (5-80, at a step of , with accumulation time 200 s per step). The morphology and porous nature characterized through scanning electron microscopy (FESEM-FEI Nova-Nano SEM-600) and transmission electron microscope (JEOL JEM-3010 with accelerating voltage at 300 kv). The Raman spectra were recorded in backscattering arrangement, using 532 nm laser excitation using 6 mw laser power. Elemental analyses were carried out using a Thermo Scientific Flash 2000 CHN analyzer. X-ray photoelectron spectroscopy (XPS) was performed on a PHI 5000 Versa Probe II scanning XPS microprobe from Physical Electronics, using X-ray radiation from an Al source equipped with a monochromator. Spectra were collected and evaluated with the MultiPak (ULVAC-PHI, Inc.) software. All binding energies were referenced to the C1s peak at ev. Adsorption studies of N 2 (77 K) of all samples were carried out using MICROMERITICS analyzer, outgassed at 423 K under high vacuum. The Raman spectrum of respective sample were collected through instrument, DXR Raman (Thermo, USA); laser wavelength: 633 nm, laser power on sample: 2mW, exposition time: 5s, 32 spectra were averaged at each spot to obtain one data point. UV-Vis diffuse reflectance spectra were recorded on samples with or without dilution in BaSO 4 using a Harrick praying mantis diffuse reflectance accessory mounted in a Perkin Elmer Lambda 650 UV Vis spectrophotometer. The photo catalyst powder was well ground with of BaSO 4 and spread onto the sampling plate prior to the measurement. The background reflectance of BaSO 4 (reference) was measured before. The Kubelka-Munk function F(R ) was calculated as F(R ) = (1 R ) 2 /2R, where R is diffuse reflectance of the sample relative to the reflectance of a standard according to the Kubelka-Munk theory. 1

2 Scheme S1. Flow chart, detailed synthetic methodology of composite Cu 2 O nanoparticles anchored on graphitic nitrogen-rich carbon matrix. 2

3 Fig S1. Nitrogen adsorption isotherms at 77 K of [Cu 3 (BTC) 2 ] and [Cu 3 (BTC) 3

4 Fig S2. Powder XRD patterns of (a) simulated pattern [Cu 3 (BTC) 2 ](1) (b) assynthesized [Cu 3 (BTC) 2 ](1) (c) desolvated[cu 3 (BTC) 2 ](1 ) (d) [Cu 3 (BTC) ](2) and it reveals structural integrity after inclusion of urea molecules on desolvated MOF. 4

5 Fig S3. SEM images of [Cu 3 (BTC) 2 ] showing octahedron morphology crystals 5

6 Fig S4. SEM images of [Cu 3 (BTC) ] composite reveals bundle of micron spheres. 6

7 Fig S5. RAMAN spectrum (a) desolvated [Cu 3 (BTC) 2 ](1 ) (b) Urea (c) hybrid [Cu 3 (BTC) ] reveals an additional band at 459 cm-1 corresponding to Cu-N band. 7

8 Fig S6a. The EDS spectra of resultant Cu 2 O@C 3 N composite, showing presence of Cu, C, N and O. 8

9 Fig S6b.Cu LMM Auger spectrum of resultant composite. Cu is expected at the binding energy around ev, while Cu 2 O is located at ev. The position and shape of the Cu LMM auger spectrum clearly proves the presence of Cu 2 O. As referee suggested, this figure we provided in supporting information of revised manuscript. Referencies: (1) Thomas Waechtler et al., Copper Oxide Films Grown by Atomic Layer Deposition from Bis(tri-n-butylphosphane)copper(I)acetylacetonate on Ta, TaN, Ru, and SiO 2, J. Electrochem. Soc. 2009, volume 156, issue 6, H453-H459 (2) Cu LMM spectra from (M.C. Biesinger, unpublished data (2013)) 9

10 Fig S7a. FE-SEM image of Cu 2 O@C 3 N composite, showing presence of bundle of nano sheets 10

11 Fig. 7b. enlarged pore size distribution calculated from NLDFT method of Cu 2 O@C 3 N 11

12 Fig S8. Uv-Vis diffuse spectra of Cu 2 O@C 3 N (band at 480 due instrumental error). 12

13 Fig.S9 (A) Schematic illustration of photocatalytic hydrogen production (cuprous oxide nanoparticle with nitrogen rich carbon matrix) in water under visible light irradiation, where EDTA as sacrificial donor. (B) Irradiation of CNx-Cu2O can result in photo indeced electron transfer by three distinct pathways, (i) Cu2O bandgap excitation; (ii) excitation of CNx (HOMOCNx LUMOCNx), followed by electron transfer from LUMOCNx into the conduction band of Cu2O (CBCu2O). (iii) Charge transfer excitation with direct optical electron transfer from HOMOCNx to CBCu2O. The CBCu2O electrons generated through pathways 1 to 3 are then transferred via copper centres of Cu2O 13

14 Fig S10. EDX spectra of carbonized sample 2, carbonized at 550 o C 14

15 Fig S11. EDX spectra of carbonized sample 2, carbonized at 700 o C 15

16 Fig S12. Comparison of photocatalytic H 2 Production of pyrolised composite [Cu 3 (BTC) at different temperatures 450 (red line), 550 (violet line),750 o C (grey line). 16

17 Table S1. Phocatalytic Activity of carbon nitride, Cuprous oxide and its composites for hydrogen production S.No or Reference Sample CoCatalyst Sacrificial Agent Light Source Hydrogen production (unit) Reference photo catalyst 1 g-c 3 N 4 by urea polymerization Phenyl urea TEOA Triethanolamine 2 Cu(OH) 2 /g- Cu(OH) 2 methanol and C 3 N 4 water 3 UiO-66/g- C 3 N 4 /P UiO-66 Pt Ascorbic acid 300 W Xe lamp (λ > 420 nm) 300 W Xe lamp (λ > 400 nm) 300 W Xe lamp (λ > 420 nm) 4 Au/g-C 3 N 4 TEOA 500 W HBO lamp (λ > 420 nm) Ni(OH) TEOA 350 W 5 Ni(OH) 2 /g- C 3 N 4 2 Xe lamp with a 400 nm 6 Ni/NiO/g-C 3 N 4 Ni/NiO TEOA 300 W Xe lamp with a 420 nm 7 Ag 2 O/g-C 3 N 4 Ag 2 O TEOA 300 W Xe lamp with a 420 nm C, N-TiO TEOA 300 W 8 C, N-TiO 2 /g- C 3 N 4 2 Xe lamp with a 400 nm 535 Pure g- μmol h 1 C 3 N 4 Enhancement and stability 9 times ~16h 48.7 Cu/g-C 3 N times μmol g 1 h 1 >28 h 14.11x10 6 g-c 3 N 4 NA M h μmol h 1 Pt/g-C 3 N 4 >15 h 7.60 Pure g- 1.1 μmol h 1 C 3 N 4 >12 h 10 Pure g- 10 μmol h 1 C 3 N 4 >16 h g-c 3 N μmol g 1 h 1 >8 h C, N-TiO μmol g 1 h 1 >32 h 9 Cu 2 O/rGO Pt/Cu2O Methanol/H2O 150W Xe lamp with 400 nm 10 -Pt TEOA 300 W Cu 2 O@g-C 3 N 4 Xe lamp with a 420 nm 11 - TEOA 300 W Cu 2 O/rGO Xe lamp with a 420 nm 12 Present work Cu 2 O@C3N - EDTA 500 W Xe lamp with a 420 nm μmol H 2 h μmol/h/g 4.53 mmol/h/g 17.6 μmol/g For 27 h Cu 2 O 3.5 NA pure g C 3 N 4 NA rgo 7.3 Pure Cu 2 O 4 27h 1. G.Zhang, X.A. Wang, J. Catal. 2013, 307, X.Zhou, Z.Luo, P. Tao, B.Jin, Z.Wu, Y. Huang, Mater. Chem. Phys. 2014, 143, R.Wang, L. Gu, J.Zhou, X. Liu, F. Teng, C. Li, Y.Shen, Y. Yuan Adv. Mater. Interfaces 2015, 2, Y.Di, X.Wang, A. Thomas, M. Antonietti, ChemCatChem 2010, 2, J.Yu, S.Wang, B. Cheng, Z.Lin, F. Huang, Catal. Sci. Technol. 2013, 3, G. Zhang, G. Li, X. Wang, ChemCatChem 2015, 7, M. Wu, J.M. Yan, X. W.Zhang, M. Zhao, Q. Jiang, J. Mater. Chem. A 2015, 3, W.Chen, T.Y. Liu, T. Huang, X.H. Liu, G. R. Duan, X. J. Yang, M. S. Chen, RSC Adv. 2015, 5, , 9. P. D. Tran, S. K. Batabyal, S. S. Pramana, J. Barber, L. H. Wong and S. C. J. Loo, Nanoscale, 2012, 4, X. Chen, S. Shen, L. Guo and S. S. Mao, Chem. Rev., 2010, 110, H. Li, X. Li, S. Kang, L. Qin, G. Li, J. Mu, Int. J. Hydrogen Energy. 2014, 24,

18 Table S2. The carbonization of 2 at various temperatures and corresponding oxidation state and nitrogen amount. Sample Copper phase Nitrogen Content (%) [Cu 3 (BTC) 2@Urea] -450 Cu 2 O (cuprous oxide) 14 [Cu 3 (BTC) 2@Urea] -550 CuO (copper oxide) 0 [Cu 3 (BTC) 2@Urea] -700 Cu (copper metal) 0 18

19 Table S3. Photocatalytic Hydrogen production at different time intervals. Sample Reaction time (h) Total amount of H 2 evolved(µmol) Cu 2 O@C 3 N Cu 2 O@C 3 N_2nd cycle Cu 2 O@C 3 N _3rd cycle Carbon nitride Cuprous oxide Cu 3 (BTC) _ Cu 3 (BTC) _

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